Since the global economics rapidly develop in recent years, the consumptions of sources of the earth are increased and the global climate is rapidly changed accordingly. Therefore, it is more and more important to lower man-made energy consumptions and carbon emissions and the effects resulted from the greenhouse effect. The proportion of the total power consumption generated by the illuminant products is always large from the electric light being invented and popularly used. Such usages of electric light not only influence biological cycles of organisms, but also cause lots of power consumptions.
According to the investigation of the American Lighting Association, household lighting accounts for 12-15% of the household utility bill. Besides, the study of Louisiana State University of U.S.A. shows that there is 20% of the total electric power of the America being used for the lighting, and half of the 20% of the total electric power is squandered due to the improper brightness sources and the user's carelessness. From this study, it is known that there are still many defects on the control of the space brightness.
The known technique for controlling the brightness of specific space usually applies additional brightness-sensing module to sense the current brightness of the specific space and then adjusts the current brightness based on the sensing result. However, the known technique cannot adjust the brightness of specific space in respond to various kinds of objects, e.g. a user, and situations. Therefore, the brightness controlled by the known technique may be over or insufficient for the user in the specific space, and the improper brightness is the consumption of power.
Employing experiments and researches full-heartily and persistently, the applicant finally conceived the method for adjusting brightness and system thereof.